When Islamic State swept into the northern Iraqi town of Sinjar in 2014, a few young Yazidi women took up arms against the militants attacking women and girls from their community.

"They took eight of my neighbours and I saw they were killing the children," Asema Dahir told Reuters last month at a checkpoint near a front line north of Mosul.

Dressed in military fatigues, the 21-year-old is now part of an all-female unit in the Kurdish peshmerga forces, which have played an important role in pushing back Islamic State in northern Iraq.

The killing and enslaving of thousands from Iraq's minority Yazidi community focused international attention on the group's violent campaign to impose its radical ideology and prompted Washington to launch an air offensive.

It also prompted the formation of this unusual 30-woman unit made up of Yazidis as well as Kurds from Iraq and neighbouring Syria. For them, only one thing matters: revenge for the women raped, beaten and executed by the jihadist militants.

Yazidi women fight ISIS
Dahir said she was stunned by the brutality of the militants, some of whom were neighbours and others from outside the area.

"They killed my uncle and took my cousin's wife who had only just married eight days earlier," she said, her piercing eyes clouding over. The bride, like thousands of other Yazidi women, is still being held by the militants.

During the firefights that raged across Sinjar in 2014, Dahir said she killed two Islamic State fighters before being shot in the leg. Reuters could not independently verify the fighters' personal accounts.

Well-worn photographs of children and families tucked into the edge of mirrors or pressed onto walls in the women's spartan barracks are reminders of what they have sacrificed to join the fight.

Haseba Nauzad, the unit's 24-year-old commander, lost her marriage. She was living with her husband in Turkey when Islamic State swept through northern Iraq and announced its so-called caliphate over areas that included traditional Kurdish lands.